Direct intraspinal installation of morphine is well demonstrated to produce analgesia of greater duration than equal or greater doses of conventional oral or parenteral morphine. This effect of intraspinal morphine is mediated via specific opiate receptors in the spinal cord dorsal horn. Continuous intraspinal morphine infusion via implanted infusion reservoir is a new alternative procedure for chronic intraspinal analgesic delivery, offering the advantages of infrequent injections and the potential access for delivery of multiple spinally active analgesics. Recent reports claim successful cancer pain control utilizing chronic intraspinal morphine where conventional narcotic regimens had failed. There is thus a need to document the comparative efficacy of management of a control group with cancer pain. The purpose of this study is to: 1) perform a comparison of outpatient cancer pain control (analgesic efficacy, functional status, cognitive function) in similar regional cancer pain syndromes (pain below diaphragm) with similar baseline narcotic requirements when managed by a). continuous intrathecal MS or b). an experienced oncologist service using a conventional narcotic regimen i.e., methadone, dilaudid, morphine, etc. 2). evaluate the relationship of CSF morphine levels to analgesic efficacy and rate of spinal morphine tolerance development. 3). perform histopathologic studies to uncover complications (if any) of chronic intraspinal catheters and neurotoxicity of chronic intrathecal morphine (if any). 4). evaluate two new intraspinal agents for their potential to produce analgesia in the cancer patient with advanced spinal morphine tolerance.
